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Regulation of the Pur‐alpha promoter by E2F‐1
Author(s) -
Darbinian Nune,
White Martyn K.,
Khalili Kamel
Publication year - 2006
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.20872
Subject(s) - alpha (finance) , e2f , microbiology and biotechnology , chemistry , biology , transcription factor , political science , genetics , gene , law , health care , cronbach's alpha
Purα is a ubiquitously expressed multifunctional nucleic acid‐binding protein that is involved in many cellular processes including transcriptional regulation, the cell cycle, oncogenic transformation, and post‐natal brain development. Previously, Purα protein was found to bind to E2F‐1, inhibit E2F‐1 transcriptional activity, and reverse the effects of ectopic E2F‐1 expression on cell growth. Also Purα binds to a GC/GA‐rich sequence within its own promoter and inhibits gene expression, that is, Purα is autoregulated. We now report that the Purα promoter (pPurα) is induced by E2F‐1 and that this activity maps to a consensus E2F‐1 binding motif that is juxtaposed to the Purα binding site. Deletion mutants of the E2F‐1 protein showed that the region between amino acid residues 88–241 is important for this activity. E2F‐1‐associated activation of the pPurα was inhibited by co‐expression of Purα, pRb, and an RNA species with specific binding to E2F‐1. Chromatin immunoprecipitation (ChIP) assay using primers that flanked the juxtaposed Purα and E2F‐1 binding sites verified the presence of Purα and E2F‐1 on the pPurα in vivo. In a Tet‐inducible cell line, Purα delayed cell cycle progression. Thus, E2F‐1 and Purα interplay appears to be involved in the regulation of Purα expression and the cell cycle. J. Cell. Biochem. 99: 1052–1063, 2006. © 2006 Wiley‐Liss, Inc.